Agreed that Chrome's history search provides similar functionality, although it is somewhat clunky to use. For example, you can not constrain results by time period.
In addition, unlike normal Google search results the history search seems to weight every word on the page equally, in recawl there is an attempt to prioritise body content whilst ignoring repeating menus & footers, and it is built on top of Lucene's excellent scoring function.
In addition for any gives search terms it learns to prefer the search results you click on, so that over time if you constantly search your history for the same or similar search terms then historical results you have already clicked on bubble up to the top.
This makes it quite a useful tool for recalling often used pages.
It also offers keywords related to your search to further help narrow down your query.
Finally, you can block certain sites that you know are not of interest from appearing in search results, again cutting down on noise.
Finally, being able to remotely search your history can come in really handy.
